Based on a literature review, Nadler, Thompson and Van Boven (2003) uncovered the four most common methods described for learning negotiation skills. The survey covered both explicit instruction and experiential/self-taught learning accounts:

These researchers conducted an experiment to see how these methods compared. In the interactive domain of negotiation, it is perhaps unsurprising that their observational learning group of subjects showed the largest increase in negotiation performance. The learning seems to have been largely tacit though, as they were the least articulate in describing the principles that had helped them improve. Analogical learning was also effective, and related to the task schemas that subjects developed in undertaking specific negotiations. Reported task schemas did not relate to performance for the other styles.